Brake for Snakes

Did you know that Grasslands National Park is home to six different species of snakes? Enjoy learning a little bit about them!

Bullsnake

Although they can reach lengths beyond 6 ft, making them one of the largest snake species in Canada, bullsnakes are non-venomous. They have a black band across their eyes and are creamy-yellow with black, brown, or reddish-brown blotches along their backs. Due to their colouration and defensive display, bullsnakes are sometimes mistaken for prairie rattlesnakes. While they put on a show hissing and ‘rattling’ their tails when feeling threatened, bullsnakes are harmless to humans!

Prairie Rattlesnake

This snake species has a distinct triangular head, vertical pupils, and usually a segmented rattle at the end of the blunt tail. They are a venomous snake species, and like other vipers sit and wait, using heat-sensing pits by their nostrils to detect heat signatures of nearby prey. Their main food source is primarily small mammals, but they will also eat birds, lizards, frogs and other snakes. Prairie rattlesnakes are slow growers. The average age of individuals reaching sexual maturity is age 5, and females only reproduce every 2 to 3 years. When females are pregnant, they can go an entire year without eating and then later give birth to a small litter (4 to18) of live young (ovoviparous). Female prairie rattlesnakes can continue to reproduce until they are 15 to 20 years old!

Prairie rattlesnakes often share winter dens with other snakes like eastern yellow-bellied racers and bullsnakes.

More information about rattlesnake safety and first aid.

Eastern Yellow-Bellied Racers

The eastern yellow-bellied racer is a long, smooth scaled, quick moving snake that is easily identifiable by its yellow-coloured belly and olive scales. These snakes like to eat insects, frogs, other snakes and small rodents and birds. Eastern yellow-bellied racers are the most at-risk snake species in Grasslands National Park. A small population size, combined with the use of communal over-wintering dens, makes them particularly vulnerable to catastrophic events such as landslides during the denning period, and road mortality. As a result, the species is listed as Threatened by the Species at Risk Act.

Plains Gartersnake

The gartersnake is likely the most common snake you will spot in the park. The plains gartersnake feeds on fish, amphibians, small mammals, worms and insects. It commonly hunts along the edge of water and may swim to escape predators. This species can live for more than 10 years. Markings consist of a bright orange or yellow stripe down the middle of the back against a black or tan background. Like the prairie rattlesnake, plains gartersnakes are ovoviparous and give birth to live young.

Plains Hog-nosed Snake

Arguably the most dramatic is the plains hog-nosed snake! Living up to its name, plains hog-nosed snakes have a pig-like, upturned nose that they use to shovel out burrows in sandy soils. When feeling scared, the species gives an award-winning performance by either flipping over and playing dead or by displaying cobra mimicry by raising and flattening their head, hissing, and mock-striking! It has a wide range in diet, from toads, frogs, salamanders, lizards, and other snakes to small rodents and invertebrates. This snake is faced with many threats including habitat loss, degradation and fragmentation from development, fire suppression, and road mortality.

Smooth Greensnake

Known for its bright green colour, this is a small snake and the least commonly seen in the park. Smooth greens at maturity are similarly sized to a pencil at 30 to 60 cm long, whereas yellow-bellied racers are closer to 100 cm long. Smooth greens are often referred to as ‘grass snakes’ due to their colouration and size, blending in as a blade of grass.

Snakes emerge from their winter dens in the spring and return in the fall before the weather gets too cold. As part of these movements, road mortality can be a locally important threat to snake recovery.

Why are snakes important?

As predator and prey, snakes are important to healthy ecosystems. Snakes that feed on small mammals help keep populations in check. If this didn’t happen, rodent populations would explode, which could lead to increased damage to crops and increasing the risk of disease transmission that can be harmful to humans.

Along with natural predators, human activity threatens the survival of prairie snakes. Persecution, habitat loss, and road mortality are some of the most prominent threats. As snakes frequently cross or bask on roads, road mortality is the biggest threat for snakes in Grasslands National Park. As a result of road mortality risks and other various threats, four of the six snake species are considered “Species at Risk” by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), ranging from ‘Threatened’ (eastern yellow-bellied racer) to ‘Special Concern’ (prairie rattlesnake, bullsnake, plains hog-nose).

How can you help?

Drive slowly—especially in high wildlife collision zones. In doing so, you have more time to notice a basking snake. Spotting snakes on roads can be difficult, so keep your eyes peeled and stop safely when in doubt.

If you spot a snake, report it to park staff in the visitor centre.

To learn more about reptile species in the park, check out the Rattlesnake Ramble. Though full for 2025, you can plan to sign up next year. Participants will join a herpetologist for a behind the scenes look at a hibernaculum and search for reptile species while learning about habitat and the challenges they face for survival.